无法从 GPS 获取位置。它总是给出 0.0 作为纬度和经度

Question

我不断从以下代码中获取 0.0 作为纬度和经度。我无法找出错误。谁能帮帮我。

这是我用来获取位置的类

public class GPS_tracker extends Service implements LocationListener {

private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;

Location location;
double latitude;
double longitude;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;

public GPS_tracker(Context context) {
    this.mContext = context;
    getLocation();
}

public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
        } else {
            this.canGetLocation = true;

            if (isGPSEnabled) {
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }

            if (isNetworkEnabled) {
                if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    // TODO: Consider calling
                    //    ActivityCompat#requestPermissions
                    // here to request the missing permissions, and then overriding
                    //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                    //                                          int[] grantResults)
                    // to handle the case where the user grants the permission. See the documentation
                    // for ActivityCompat#requestPermissions for more details.
                    // return TODO;
                }
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }

        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}

public void stopUsingGPS() {
    if (locationManager != null) {
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            // return;
        }
        locationManager.removeUpdates(GPS_tracker.this);
    }
}


public double getLatitude() {
    if (location != null) {
        latitude = location.getLatitude();
    }
    return latitude;
}


public double getLongitude(){
    if(location != null){
        longitude = location.getLongitude();
    }
    return longitude;
}


public boolean canGetLocation() {
    return this.canGetLocation;
}


public void showSettingsAlert(){
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
    alertDialog.setTitle("GPS is settings");
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int which) {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            mContext.startActivity(intent);
        }
    });

    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });


    alertDialog.show();
}

@Override
public void onLocationChanged(Location location) {
}

@Override
public void onProviderDisabled(String provider) {
}

@Override
public void onProviderEnabled(String provider) {
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}

@Override
public IBinder onBind(Intent arg0) {
    return null;
}
}

这些是我在清单文件中包含的权限

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

这是我正在使用的点击功能

public void onClick(View view) {
    if(view == btnGPS){
        gps=new GPS_tracker(Login.this);
        if(gps.canGetLocation()){
            double latitude=gps.getLatitude();
            double longitute=gps.getLongitude();
            Toast.makeText(getApplicationContext(), "Lat:"+latitude+"Long:"+longitute, Toast.LENGTH_SHORT).show();
        }
        else {
            gps.showSettingsAlert();
        }
    }
}

Answer 1

由于位置请求方法无法获取位置的问题。您需要为正确的位置设置精度模式。这是我的工作代码，试试这个

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

    private GoogleMap mMap;
    GoogleApiClient mGoogleApiClient;
    Location mLastLocation;
    Marker mCurrLocationMarker;
    LocationRequest mLocationRequest;
    PendingResult<LocationSettingsResult> result;
    final static int REQUEST_LOCATION = 199;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            checkLocationPermission();
        }
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }



    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        //Initialize Google Play Services
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                buildGoogleApiClient();
                createLocationRequest();
                mMap.setMyLocationEnabled(true);
            }
        }
        else {
            buildGoogleApiClient();
            createLocationRequest();
            mMap.setMyLocationEnabled(true);
        }
    }

    private void createLocationRequest() {
        mLocationRequest = new LocationRequest();


        mLocationRequest.setInterval(10000);


        mLocationRequest.setFastestInterval(10000);

        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    }

    protected synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnected(Bundle bundle) {

        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(30 * 1000);
        mLocationRequest.setFastestInterval(5 * 1000);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(mLocationRequest);
        builder.setAlwaysShow(true);

        result = LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());

        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:


                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:

                        try {

                            status.startResolutionForResult(
                                    MapsActivity.this,
                                    REQUEST_LOCATION);
                        } catch (IntentSender.SendIntentException e) {
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:

                        break;
                }
            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        Log.d("onActivityResult()", Integer.toString(resultCode));

        switch (requestCode)
        {
            case REQUEST_LOCATION:
                switch (resultCode)
                {
                    case Activity.RESULT_OK:
                    {
                        Toast.makeText(MapsActivity.this, "Location enabled by user!", Toast.LENGTH_LONG).show();

                        mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
                        break;
                    }
                    case Activity.RESULT_CANCELED:
                    {
                        Toast.makeText(MapsActivity.this, "Location not enabled, user cancelled.", Toast.LENGTH_LONG).show();
                        break;
                    }
                    default:
                    {
                        break;
                    }
                }
                break;
        }
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onLocationChanged(Location location) {

        mLastLocation = location;
        if (mCurrLocationMarker != null) {
            mCurrLocationMarker.remove();
        }

        LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(latLng);
        markerOptions.title("Current Position");
        markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
        mCurrLocationMarker = mMap.addMarker(markerOptions);

        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        mMap.animateCamera(CameraUpdateFactory.zoomTo(11));

        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

    }

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
    public boolean checkLocationPermission(){
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)) {


                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                        MY_PERMISSIONS_REQUEST_LOCATION);


            } else {
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                        MY_PERMISSIONS_REQUEST_LOCATION);
            }
            return false;
        } else {
            return true;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    if (ContextCompat.checkSelfPermission(this,
                            Manifest.permission.ACCESS_FINE_LOCATION)
                            == PackageManager.PERMISSION_GRANTED) {

                        if (mGoogleApiClient == null) {
                            buildGoogleApiClient();
                        }
                        mMap.setMyLocationEnabled(true);
                    }

                } else {

                    Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
                }
                return;
            }

        }
    }
}

Answer 2

您是否授予访问位置权限的权限？

public class LocationUtil extends Service implements LocationListener {
    private static final String TAG = LocationUtil.class.getSimpleName();

    public Context mContext;

    // flag for GPS status
    private boolean isGPSEnabled = false;
    // flag for network status
    private boolean isNetworkEnabled = false;
    // flag for passive status
    private boolean isPassiveEnabled = false;

    private boolean canGetLocation = false;

    private Location location; // location
    private double latitude; // latitude
    private double longitude; // longitude

    // The minimum distance to change Updates in meters
    private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0;
    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES = 0;
    // Declaring a Location Manager
    protected LocationManager locationManager;

    public LocationUtil(Context context) {
        this.mContext = context;
        getLocation();
    }

    public LocationUtil() {
    }

    public Location getLocation() {
        try {
            location = null;
            locationManager = (LocationManager) mContext
                    .getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            // getting network status
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            // getting passive status
            isPassiveEnabled = locationManager
                    .isProviderEnabled(LocationManager.PASSIVE_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled && !isPassiveEnabled) {
                showSettingsAlert();
            } else {
                this.canGetLocation = true;
                if (checkPermission()) {
                    if (isNetworkEnabled) {
                        locationManager.requestLocationUpdates(
                                LocationManager.NETWORK_PROVIDER,
                                MIN_TIME_BW_UPDATES,
                                MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                        Log.d(TAG, "Network");
                        if (locationManager != null) {
                            location = locationManager
                                    .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                            if (location != null) {
                                latitude = location.getLatitude();
                                longitude = location.getLongitude();
                                return location;
                            }
                        }
                    }
                    // if GPS Enabled get lat/long using GPS Services
                    if (isGPSEnabled) {
                        if (location == null) {
                            locationManager.requestLocationUpdates(
                                    LocationManager.GPS_PROVIDER,
                                    MIN_TIME_BW_UPDATES,
                                    MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                            Log.d(TAG, "GPS Enabled");
                            if (locationManager != null) {
                                location = locationManager
                                        .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                                if (location != null) {
                                    latitude = location.getLatitude();
                                    longitude = location.getLongitude();
                                    return location;
                                }
                            }
                        }
                    }
                    if (isPassiveEnabled) {
                        if (location == null) {
                            locationManager.requestLocationUpdates(
                                    LocationManager.PASSIVE_PROVIDER,
                                    MIN_TIME_BW_UPDATES,
                                    MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                            Log.d(TAG, "Passive Enabled");
                            if (locationManager != null) {
                                location = locationManager
                                        .getLastKnownLocation(LocationManager.PASSIVE_PROVIDER);
                                if (location != null) {
                                    latitude = location.getLatitude();
                                    longitude = location.getLongitude();
                                    return location;
                                }
                            }
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return location;
    }

    /**
     * Stop using GPS listener
     * Calling this function will stop using GPS in your app
     */
    public void stopUsingGPS() {
        if (locationManager != null) {
            locationManager.removeUpdates(LocationUtil.this);
        }
    }

    private boolean checkPermission() {
        int permission = ContextCompat.checkSelfPermission(mContext, ACCESS_FINE_LOCATION);
        if (permission == PackageManager.PERMISSION_GRANTED) {
            return true;
        } else {
            return false;
        }
    }

    /**
     * Function to get latitude
     */
    public double getLatitude() {
        if (location != null) {
            latitude = location.getLatitude();
        }
        // return latitude
        return latitude;
    }

    /**
     * Function to get longitude
     */
    public double getLongitude() {
        if (location != null) {
            longitude = location.getLongitude();
        }
        // return longitude
        return longitude;
    }

    /**
     * Function to check GPS/wifi enabled
     *
     * @return boolean
     */
    public boolean canGetLocation() {
        return this.canGetLocation;
    }

    /**
     * Function to show settings alert dialog
     * On pressing Settings button will lauch Settings Options
     */
    public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");
        // Setting Dialog Message
        alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
        // On pressing Settings button
        alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });
        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        // Showing Alert Message
        alertDialog.show();
    }

    @Override
    public void onLocationChanged(Location location) {
        getLocation();
    }

    @Override
    public void onProviderDisabled(String provider) {
    }

    @Override
    public void onProviderEnabled(String provider) {
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        getLocation();
    }


    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }
}

Answer 3

不要使用 GPSTracker。这段代码完全被破坏了。众所周知，它已损坏多年。它有时会起作用，但它的设计缺陷使其无法修复。特别是 irt 不了解启用的提供程序和具有位置修复之间的区别，并且依赖于永远不应该依赖的 getlastKnownLocation。

几年前我写了一篇关于此的博客文章，说明了它为什么会损坏，并提供了更好的解决方案。扔掉 GPTracker 并使用它，或者找到另一个解决方案。但是如果不深入研究位置的实际工作原理，您拥有的代码将无法使用。